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Title: Augmented vagal heart rate modulation in active hypoestrogenic pre-menopausal women with functional hypothalamic amenorrhoea
Authors: O'Donnell, Emma
Goodman, Jack M.
Morris, Beverley L.
Floras, John S.
Harvey, Paula J.
Keywords: Hypothalamus
Vagus nerve
Analysis of variance
Cross-sectional studies
Renin-angiotensin system
Blood pressure
Heart rate
Young adult
Issue Date: 2015
Publisher: © Authors; published by Portland Press Limited
Citation: O'DONNELL, E. ... et al., 2015. Augmented vagal heart rate modulation in active hypoestrogenic pre-menopausal women with functional hypothalamic amenorrhoea. Clinical Science, 129 (10), pp. 885 - 893.
Abstract: Compared with eumenorrhoeic women, exercise-trained women with functional hypothalamic amenorrhoea (ExFHA) exhibit low heart rates (HRs) and absent reflex renin-angiotensin-system activation and augmentation of their muscle sympathetic nerve response to orthostatic stress. To test the hypothesis that their autonomic HR modulation is altered concurrently, three age-matched (pooled mean, 24 ± 1 years; mean ± S.E.M.) groups of women were studied: active with either FHA (ExFHA; n=11) or eumenorrhoeic cycles (ExOv; n=17) and sedentary with eumenorrhoeic cycles (SedOv; n=17). Blood pressure (BP), HR and HR variability (HRV) in the frequency domain were determined during both supine rest and graded lower body negative pressure (LBNP; -10, -20 and -40 mmHg). Very low (VLF), low (LF) and high (HF) frequency power spectra (ms(2)) were determined and, owing to skewness, log10-transformed. LF/HF ratio and total power (VLF + LF + HF) were calculated. At baseline, HR and systolic BP (SBP) were lower (P<0.05) and HF and total power were higher (P<0.05) in ExFHA than in eumenorrhoeic women. In all groups, LBNP decreased (P<0.05) SBP, HF and total power and increased (P<0.05) HR and LF/HF ratio. However, HF and total power remained higher (P<0.05) and HR, SBP and LF/HF ratio remained lower (P<0.05) in ExFHA than in eumenorrhoeic women, in whom measures did not differ (P>0.05). At each stage, HR correlated inversely (P<0.05) with HF. In conclusion, ExFHA women demonstrate augmented vagal yet unchanged sympathetic HR modulation, both at rest and during orthostatic stress. Although the role of oestrogen deficiency is unclear, these findings are in contrast with studies reporting decreased HRV in hypoestrogenic post-menopausal women.
Description: The final version of record is available at http://www.clinsci.org/content/ppclinsci/129/10/885.full.pdf
Sponsor: This work was supported by a Pfizer Cardiovascular Independent Research Award [grant number NRA 3840028] to P.J.H.
Version: Accepted for publication
DOI: 10.1042/cs20150209
URI: https://dspace.lboro.ac.uk/2134/20606
Publisher Link: http://dx.doi.org/10.1042/cs20150209
ISSN: 0143-5221
Appears in Collections:Published Articles (Sport, Exercise and Health Sciences)

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